George Zimmerman is greeted by defense counsel Don West at the start of the 20th day of his trial in Seminole circuit court, in Sanford, Fla., Monday, July 8, 2013. Zimmerman is charged with 2nd-degree murder in the fatal shooting of Trayvon Martin, an unarmed teen, in 2012. (Joe Burbank/Orlando Sentinel/POOL) newsgate CCI B583043294Z.1

Sondra Osterman, a friend of George Zimmerman, listens to the 911 tape while testifying, on the 20th day of his trial in Seminole circuit court, in Sanford, Fla., Monday, July 8, 2013. Zimmerman is charged with 2nd-degree murder in the fatal shooting of Trayvon Martin, an unarmed teen, in 2012. (Joe Burbank/Orlando Sentinel)

Mark Osterman, a friend of George Zimmerman, describes the type of gun Zimmerman owned while testifying, on the 20th day of the Zimmerman trial in Seminole circuit court, in Sanford, Fla., Monday, July 8, 2013. Zimmerman is charged with 2nd-degree murder in the fatal shooting of Trayvon Martin, an unarmed teen, in 2012. (Joe Burbank/Orlando Sentinel)

LeAnne Benjamin, a friend of George Zimmerman, smiles while identifying him in court during her testimony on the 20th day of his trial in Seminole circuit court, in Sanford, Fla., Monday, July 8, 2013. Zimmerman is charged with 2nd-degree murder in the fatal shooting of Trayvon Martin, an unarmed teen, in 2012. (Joe Burbank/Orlando Sentinel)

John Donnelly, a friend of George Zimmerman, cries on the witness stand after listening to screams on the 911 tape entered in evidence, on the 20th day of Zimmerman's trial in Seminole circuit court, in Sanford, Fla., Monday, July 8, 2013. Donnelly identified the screams as belonging to Zimmerman. Zimmerman is charged with 2nd-degree murder in the fatal shooting of Trayvon Martin, an unarmed teen, in 2012. (Joe Burbank/Orlando Sentinel)

Witnesses for the defense will continue to testify today in the George Zimmerman trial.

After the prosecution rested on Friday, jurors heard from the first witnesses for the defense, including George Zimmerman's mother, Gladys. Friday also brought Trayvon Martin's mother, Sybrina Fulton, to the stand. Both mothers testified they heard their sons voice screaming for help in the 911 call where the shot can be heard.

Zimmerman is charged with the second-degree murder of 17-year-old Martin, who he shot and killed Feb. 26, 2012 in The Retreat at Twin Lakes neighborhood in Sanford. Zimmerman has maintained the shooting occurred in self-defense after Martin attacked him.

Check back throughout the day for updates from the courtroom. The most recent updates will be at the top of the page.

5 p.m.

Judge Nelson has ruled that the toxicology report will be introduced and the state will be allowed to cross examine or call a rebuttal witness.

4:47 p.m.

Prosecutor John Guy is arguing that the admission of Trayvon Martin's toxicology report should not be relevant because the presence of marijuana in Martins was so small and Zimmerman did not know about it. West argued that the medical examiner said the amount found in his system would affect him. West said jurors already saw Martin "swaying" in 7-eleven, and heard Zimmerman say Martin looked like he was on drugs. West said it supports their claim of self-defense.

4:44 p.m.

Mantei said there are two violations. Willful and inadvertent. He said he hasn't heard anything indicating this wasn't a willful violation. Nelson ruled that Donnellys testimony will not be stricken.

4:41 p.m.

Judge Nelson: what difference would it have made? What would the state have done differently?

Mantei argued that their cross examination was hindered because the defense knew that Donnelly was going to testify a certain way and the state was not able to be prepared. O'Mara said he thought the state failed to show any prejudice. "I thought their cross examination of mr. Donnelly was quite good," said O'Mara.

4:29 p.m.

Judge Nelson will hear several items, including the request by the prosecution to strike Donnellys testimony because the state is arguing that the defense knew Donnelly would testify that Zimmerman was the voice in the 911 call. The state is claiming the defense did not properly notify the state about the information.

4:27 p.m.

Jurors are leaving the courtroom.

4:23 p.m.

Lee said, "the evidence in testimony gave us an indication who was screaming on the tape."

4:20 p.m.

Lee said the city manager made the decision not to include him in the playing of the tapes for Martin's family.

4:18 p.m.

Lee said his recommendation was to play the tapes individually, and his understanding was the tapes were played in a group setting in the mayors office. It is normally an event that would be handled by law enforcement, he said. He said he offered to be present, but was excluded from the room.

4:15 p.m.

O'Mara asked if Lee was aware that the decision was made to play the 911 call to the Martin family. He said he was aware, and O'Mara continued to question Lee on the typical format to play an audio call - that witnesses who are listening to the call be separated so they would not be influenced by each other.

4:12 p.m.

Bill Lee Jr. is the former police chief of the Sanford Police Department. He was born and raised in Sanford and worked as chief from May 2011 to June 2012. He said he was in a supervisory role in the police department.

4:10 p.m.

O'Mara asked if Tracy Martin ever told Benjamin Crump, his attorney, to say that the call had been cleared up and he could hear it better. The defense has now called Chief Bill Lee to the stand.

4:09 p.m.

Tracy Martin said the day they listened "I was just trying to figure out why on feb, 26,2012 why did the defendant get out of his vehicle and chase my son."

4:07 p.m.

"I was listening to my sons last cries for help before his life was taken," said Tracy Martin.

3:59 p.m.

Tracy Martin said he did not listen to the tape between the time it was played at the police department on Feb. 28 and at the mayor's office on March 16. "it's very difficult to think that Trayvon is not living. As I've said over and over again that was my best friend in life," said Tracy Martin.

3:58 p.m.

"After listening to the tape about 20 times I said I knew that that was Trayvon's voice," said Tracy Martin.

3:55 p.m.

Tracy Martin said he never requested to listen to the tape again. "I never told anyone that I listened to a cleaned up version of the tape," said Tracy Martin. He said he never told Sybrina Fulton, Trayvon's mother, that he had heard the tape. When it was played in front of the whole family at the mayor's office later, he said he never informed anyone that he had heard the tape before.

3:52 p.m.

Tracy Martin said initially he was headed to the station a few days after the shooting to make sure Trayvon had been identified. During this visit Tracy listened to the Lauer 911 call. Tracy Martin said he told Serino "I can't tell," about hearing Trayvon martins voice in the 911 call. Tracy Martin said he never said it wasn't Trayvon's voice in the call.

3:51 p.m.

The defense has called Tracy Martin, Trayvon Martin's father, to the stand.

3:10 p.m.

"A one-minute round can feel like an eternity if you're not in the condition for it," said Pollock.

3:06 p.m.

Pollock said the Zimmerman lost about 50 pounds during the time he was going to the gym. Mantei is addressing the "first blow advantage," and asking if it might potentially put you in a worse position, rather than getting someone ahead in a fight.

3:04 p.m.

Mantei has begun his cross-examination of Pollock. Pollock said his slogan for the gym is "learn without getting hit."

3:02 p.m.

Pollock said he would describe Zimmerman as "non-athletic." "He's just physically soft.... He was predominantly fat, not a lot of muscle," said Pollock.

3 p.m.

Pollock said he saw Zimmerman a few days after the incident and Zimmerman had black eyes and band aids. He said other than the physical stuff, Zimmerman looked "emotional traumatized." He looked like a human being who had experienced something and was traumatized, said Pollock.

2:58 p.m.

Pollock said when Zimmerman came to the gym he was "grossly obese." He said Zimmerman did a good job and losing weight but lacked the athleticism to really advance.

2:56 p.m.

Pollock said Zimmerman was still learning how to punch, "he still hadn't learned how to effectively punch," he said.

2:54 p.m.

Pollock said Zimmerman never made it into the ring during his training at the gym.

2:51 p.m.

Pollock said Zimmerman began coming back in the gym around January 2012 and stopped coming after the incident. "He was very diligent, very coachable, very easy to work with," said Pollock. He said when Zimmerman stopped coming in the gym he was probably at a 1.5 or 1 on a scale from 1 to 10.

2:48 p.m.

Pollock called Zimmerman "a beginner" when he came to the gym. He said on a scale of 1 to 10 and and pollock rated him a .5 when he arrived at the gym. He said Zimmerman trained at the gym for about a year, with a few months of hiatus because of school.

2:45 p.m.

Pollock is testifying about Zimmerman's experience at his gym. He said Zimmerman picked his classes based on his school and work schedule was. Zimmerman originally wanted to learn how to box, but ended up taking grappling classes. He said they put Zimmerman on a diet. He said Zimmerman came to about 2-3 sessions a week, with each session taking about two hours.

2:44 p.m.

"Generally if someone has the skill to put someone on the bottom, they have the skill to keep them there," said Pollock.

2:43 p.m.

Pollock has described the concept of "shrimping" where a person could get from under a mounted position.

2:41 p.m.

Pollock is demonstrating a "mounted position" on O'Mara for the jury. O'Mara is on the ground with Pollock on top of him.

2:36 p.m.

"Do you know what the term 'ground and pound' means?" Asked O'Mara.

"Yes," said Pollock.

Pollock said a "ground and pound" is taking someone onto the ground and keeping them on the ground, then begin striking them downward. "Ground and pound" was the term used by Witness John Good when describing how Martin was beating Zimmerman, according to his account.

2:33 p.m.

Pollock is giving his background, as far as what he has trained in and what sports he has been involved in. O'Mara has begun to question him on mixed martial arts, which Zimmerman studied at his gym.

2:29 p.m.

The defense has called Adam Pollock to the stand. He owns a gym, Kokopelli's Gym, and is a trainer.

2:28 p.m.

"No there was no doubt that he was telling us that wasn't his sons voice," said Singleton.

2:24 p.m.

Ofc. Singleton was called back to the stand. She said that Tracy Martin said it was not his son's voice on the tape.

"I could feel how he must feel because I have children. I felt horrible for him," said Singleton.

2:21 p.m.

O'Mara questioned Serino about Zimmerman's statement of, "That doesn't even sound like me," after hearing the Lauer 911 call. Serino said he did not take it as Zimmerman's denial, but as Zimmerman did not recognize his own voice.

2:20 p.m.

"Do you have any concern that he understood your question and answered it by saying no?" Said O'Mara

"No," answered Serino.

2:16 p.m.

Serino said the identification made by Martin at that point became a clear part of the investigation because he had statements from John Good and Ofc. Timothy Smith that the voice screaming in the call would have Zimmerman. Serino said Tracy Martin never called him to listen to the tape again or to change his answer.

2:14 p.m.

"It could be construed as denial" said Serino in response to de la Rionda inquiring about parents grief and crying out, "no" in disbelief.

2:12 p.m.

"It was trying for me," said Serino. Serino said he either said, "Do you recognize the voice?" Or "Is that your son's voice in the background?" Serino said he interpreted Tracy Martins answer as "no." He said he saw Tracy Martin's mouth move when he answered.

2:09 p.m.

Serino said Singleton was not there. Cross examination has begun and Serino said he was being as sensitive as possible to Tracy Martin's needs during the playing of the 911 calls. De la Rionda asked if Tracy Martin's response and interest in what was going on was normal, and Serino confirmed. "It was a very emotional moment, yessir," said Serino.

2:04 p.m.

Serino said the call was audible and was played off of a computer. Serino called Tracy Martin's response "emotional." He said he asked if that was his son's voice in the background. He said Tracy Martin looked away and under his breath said "no."

2 p.m.

O'Mara asked Serino about his interview with Tracy Martin. Serino said he was bringing them up to speed on what happened and why there had been no arrest. He then played the 911 call to him while he was at his desk in the police department.

1:46 p.m.

The defense called Ofc. Chris Serino to the stand. Serino was the lead investigator for the case while the Sanford Police Department handled it.

1:45 p.m.

Singleton said the interview took place two days after Martin's death, and there was some concern on Tracy Martin's part that there had not been an arrest. She said Tracy Martin's girlfriend was with them, and Serino was explaining why and arrest had not been made. She said during the interview the Lauer 911 call was played for Tracy Martin.

"He was very upset, he was very sad. He hung his head and cried," said Singleton.

1:40 p.m.

O'Mara began to question Singleton about an interview between Ofc. Chris Serino and Tracy Martin, Trayvon Martin's father, which she was present for. De la Rionda objected on hearsay and they have approached the bench for a discussion with Judge Nelson.

1:38 p.m.

Court is back in session and the defense has called Ofc. Doris Singleton to the stand. Singleton was the first to interview Zimmerman following the incident on Feb. 26, 2012.

12:11 p.m.

Court will recess for lunch until 1:30 p.m.

12:06 p.m.

O'Mara is clarifying with Donnelly - Donnelly has said that all of the screams heard in the background are George Zimmerman's voice. "This courtroom is about truth," said Donnelly.

12 p.m.

De la Rionda is playing the non-emergency call for Donnelly. Donnelly has acknowledged that it is Zimmerman on the call. "He's speaking to law enforcement and trying to give them information," said Donnelly. On the 911 call: "That was absolutely George Zimmerman," said Donnelly.

11:56 a.m.

Donnelly said he donated $2,500 to Zimmerman's defense fund and $500 to his personal website. He said he also paid $1,700 for suits for Zimmerman to wear to court. " He is my very dear friend and I consider him a son," said Donnelly.

11:55 a.m.

De la Rionda has begun cross-examination of Donnelly. He asked Donnelly about listening to the call for the first time this Saturday. Donnelly said he and his wife try not to discuss anything much of the case.

11:50 a.m.

Following listening to the 911 call O'Mara asked him whose voice was screaming in the background.

"There is absolutely no doubt in my mind that is George Zimmerman," said Donnelly. "And I wish to god I did not have that ability to understand that."

11:47 a.m.

Donnelley said that often times when you hear a call for help, you will know who it is going to be before you get there. He said he haven't listened to the tape of the 911 call because,"It can be very distressing," he said.

11:45 a.m.

He is explaining how soldiers may yell for a lot of reasons, and in some cases they are yelling for help.

11:43 a.m.

Donnelly was about to explain what it is like to care for people you know on the battlefield and de la Rionda requested to approach the bench. Council is speaking with judge Nelson now.

11:41 a.m.

He said he has close experience with Zimmerman's voice, including during the campaign when they were yelling. He said he was combat medic in the Vietnam War. He is describing the change in voices once people are in combat, compared to hanging out with them during the day.

11:31 a.m.

The defense has called John Donnelly to the stand. He is a retired physicians assistant and now works on medical malpractice cases. He is a friend of Zimmerman's, and husband to Benjamin. He said they became good friends with George Zimmerman and said "he was very interested in business and starting his own business." He said he taught Zimmerman how to tie a knot in a tie.

11:23 a.m.

De la Rionda is crossing again. Benjamin has left the stand.

11:18 a.m.

O'Mara has begun his redirect, and is questioning Benjamin about whether or not she heard Zimmerman acting with "ill-will and hatred,"

"It seemed to me that Mr. De la Rionda was trying to make it sound heightened," said Benjamin. She said she has heard her sons curse.

11:15 a.m.

"I heard those words but I don't think it was in a heightened state of alert," said Benjamin. She said she has met people who use curse words in a conversation and "it does not always indicate that it is an alarming situation."

11:09 a.m.

De la Rionda is playing the non-emergency call made by Zimmerman for Benjamin. She has listened to the call several times and de la Rionda keeps asking about what Zimmerman is saying, and how he's saying it. De la Rionda is asking her

To focus on the cursing in the call. "I don't think he was in an extremely excited state," she said.

10:56 a.m.

She said she has heard his voice as "very similar," because of the campaign they had worked together on. De la Rionda questioned her about the voice in the call. "It is George Zimmerman," she said.

"that's your opinion," said de la Rionda.

10:54 a.m.

Benjamin said she does not remember the first time she heard the Lauer 911 call. She said she believed she heard it "in the background" on the television while she was in the kitchen. "It was on tv, probably related to the news," she said.

10:51 a.m.

Benjamin is being interviewed by de la Rionda. She confirmed that they have donated more than $2,500 to Zimmerman to help him.

10:49 a.m.

O'Mara is playing the Lauer 911 call. Benjamin said it is Zimmerman's voice in the background.

"I know his voice," she said. She said during the political campaign they were "whooping it up" so she knows what he sounds like when he gets loud or excited.

10:45 a.m.

Benjamin said Zimmerman called her and she was not aware of the conditions or the news story, so they "just talked." It was within a couple of weeks after the event, she said.

"It was very important to me to offer my support," she said. "Mostly we just talked."

She said her and her husband have helped him out financially. "We have on occasion taken them some food." Her husband took him to Men's Warehouse and bought him some clothing in preparation of the trial.

"I just believe in telling what I know," she said.

10:44 a.m.

"We encouraged him to potentially go to college," said Benjamin. She said she felt there was time later for Zimmerman to start a business and that he should go back to school. She also said she noticed Zimmerman was tutoring some young children and "was very proud of that."

10:42 a.m.

Benjamin said Zimmerman had an interest in starting a business and questioned her about her business. She said they began doing things more socially together, and eventually served on a campaign for someone running in Lake Mary.

10:37 a.m.

Leanne Benjamin has taken the stand. She said she met Zimmerman in late 2002 or early 2003. She said she worked in real estate and she referred her customers to him when he worked at an insurance company. She said they have maintained a relationship over the years. Shellie and George Zimmerman are friends with her and her husband.

10:34 a.m.

O'Mara is trying to determine how much she knew about the case. She said she simply believed the voice to be George Zimmerman's, and she would testify if she didn't think it was him also. She has been excused from the witness stand.

10:32 a.m.

"So when you heard the tape you wanted to believe if was George Zimmerman screaming for help?" Asked Guy.

"The voice I heard I recognized to be George Zimmerman's." she said.

10:30 a.m.

Assistant State Attorney John Guy questioned Russo about the first time she heard the tape. She said she knew he was out of work but was unsure he was being investigated.

10:26 a.m.

O'Mara is playing the Lauer 911 call for Russo. She said she has heard the tape before, less than half a dozen times. She said she heard it on the news. In her opinion, she said, it was Zimmerman's voice screaming in the background.

Russo said she would consider herself a friend and co-worker of Zimmerman, and said she kept in touch with him during the time they were not working together, as well. She said she has heard his voice in different ways both in English and Spanish. "I've heard him laughing, not yelling." She said.

10:22 a.m.

The defense has excused Osterman, but he is subject to recall. They have now called Geri Russo, who works for Digital Risk and worked with Zimmerman.

10:19 a.m.

O'Mara questioned Osterman about firing a weapon more than once, and when you would do that. He also questioned him about Zimmerman's holster and its concealment.

"You wear what is comfortable to you and you wear what is going to be effective," said Osterman.

10:16 a.m.

O'Mara asked Osterman during redirect about placing a bullet into the chamber, and whether or not he would recommend that.

"It's better to have it and not need it, than need it and not have it." Said Osterman.

10:14 a.m.

"There's a difference right, between what a person and a police officer can do?" Asked de la Rionda.

"The authority is different," said Osterman.

10:12 a.m.

Osterman said it is standard for police to keep one in the chamber, but he agreed that people with concealed weapons licenses are not law enforcement.

10:10 a.m.

De la Rionda is questioning Osterman about their training with guns, and when he believes is the right time holster the gun when there is a threat. They are speaking about hypothetical situations when you would or would holster your weapon.

10:07 a.m.

De la Rionda has begun his questioning of Osterman.

"But you made him a better shooter?" Asked de la Rionda.

"I hope so," said Osterman.

10:04 a.m.

O'Mara played the 911 call to Osterman. "I thought it was George," he said.

10 a.m.

Osterman said he told Zimmerman to do what felt comfortable, and said they've practiced shooting with their non-dominant hand. "Whichever hand can get to the firearm, that's the one you would use," he said.

9:58 a.m.

He shoots right-handed, said Osterman. But, he said, he believed Zimmerman was left-handed when writing.

9:54 a.m.

Osterman said they chose the Keltec 9mm because it did not have an external safety. He said "if you're in a tussle with someone and you're in a situation that's so stressful," the external safety may stop you from being able to shoot.

"I suggested that you keep one loaded in the chamber," said Osterman. "That extra step sometimes is the difference between life and death."

9:52 a.m.

O'Mara asked Osterman about how Zimmerman came to get a concealed weapons license. He said they had discussions on firearm safety "often."

"And George was very safe all the time," he said.

9:50 a.m.

O'Mara called Mark Osterman, a Federal Air Marshall and "best friend" to Zimmerman.

9:45 a.m.

Osterman said the cries in the 911 call seemed to be continuous. O'Mara asked Osterman after hearing the entire non-emergency call if she felt he was acting "spiteful or hateful." She said she did not feel that way.

9:39 a.m.

Osterman, despite hearing the non-emergency call several times, says she cannot hear Zimmerman say, "---- punks." They are now playing the entire call for her.

9:37 a.m.

The defense has requested that the entire tape be played for Osterman.

9:33 a.m.

O'Mara asked Osterman if she had the impression that Zimmerman was acting "angry or with ill-will." She said no. She said she is sure it is Zimmerman screaming in the 911call and remembers Shellie's reaction when she heard it. De la Rionda asked Osterman if the language Zimmerman uses is friendly. She said she does not take the language as him being angry.

9:30 a.m.

De la Rionda is playing the non-emergency call Zimmerman made the night Martin was killed. Osterman said she recognizes the voice as Zimmerman's, and said she has not heard him scream before, the way he does in the 911 call.

9:28 a.m.

Cross examination by Assistant State Attorney Bernie de la Rionda has begun. He is questioning Osterman about a book her and her husband wrote, with the profits benefitting Zimmerman. She said she has heard the 911 call several times on the news and knows it is Zimmerman screaming during the call.

9:23 a.m.

Osterman has testified that she is good friends with the Zimmerman's and has heard Zimmerman's voice a lot over the years. She said she has not been in contact with Zimmerman because of the case, but as far as she is concerned they are still friends. Defense attorney Mark O'Mara played the 911 call where screaming can be heard. He asked Osterman if she knew who was screaming.

"Yes, definitely. It's Georgie," she said.

9:18 a.m.

The defense has called Sondra Osterman to the stand. She is wife to Mark Osterman, a family friend of George and Shellie Zimmerman.